title: Signaling molecules and cell death in Melissa officinalis plants exposed to ozone.
abstract: The study focuses on the interaction between reactive oxygen species and hormones that regulate the programmed cell death in plants of Melissa officinalis exposed to ozone. Interaction between hormone and redox signaling pathways has been investigated in ozone-stressed (200 ppb, 5 h) lemon balm to verify if the response resembles the biotic defense reactions. In comparison to controls, plants exhibited foliar injury and the cell death was induced by (1) biphasic production of hydrogen peroxide and superoxide radical; (2) hormonal regulation of ozone-induced lesion formation with a significant production of ethylene, salicylic, jasmonic and abscisic acid; (3) ozone degradation to reactive oxygen species and their detoxification by some enzymatic (such as superoxide dismutase) and non-enzymatic antioxidant systems (such as ascorbic acid, glutathione and carotenoids), that worked in cooperation without providing a defense against free radicals (such as confirmed by the modification of the antioxidant properties of leaf tissue). This integrated view showed that reactive oxygen species interact with hormonal signaling pathway regulating cell death and the sensitivity of lemon balm to ozone.
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Pellegrini
authors.forename: Alice
authors.initials: A
authors.lastname: Trivellini
authors.forename: Alessandra
authors.initials: A
authors.lastname: Campanella
authors.forename: Alessandra
authors.initials: A
authors.lastname: Francini
authors.forename: Giacomo
authors.initials: G
authors.lastname: Lorenzini
authors.forename: Cristina
authors.initials: C
authors.lastname: Nali
authors.forename: Paolo
authors.initials: P
authors.lastname: Vernieri
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D019803:Glutathione Disulfide / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D031334:Melissa / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D010126:Ozone / Q000494:pharmacology*; D010860:Pigments, Biological / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors
chemical_list: D000975:Antioxidants; D010860:Pigments, Biological; D013481:Superoxides; D017665:Hydroxyl Radical; D010126:Ozone; D000040:Abscisic Acid; D006861:Hydrogen Peroxide; D001205:Ascorbic Acid; D019803:Glutathione Disulfide